Cooperating Distributed Grammar Systems of Finite Index Working in Hybrid Modes

We study cooperating distributed grammar systems working in hybrid modes in connection with the finite index restriction in two different ways: firstly, we investigate cooperating distributed grammar systems working in hybrid modes which characterize programmed grammars with the finite index restriction; looking at the number of components of such systems, we obtain surprisingly rich lattice structures for the inclusion relations between the corresponding language families. Secondly, we impose the finite index restriction on cooperating distributed grammar systems working in hybrid modes themselves, which leads us to new characterizations of programmed grammars of finite index.Comment: In Proceedings AFL 2014, arXiv:1405.527

On the Degree of Team Cooperation in CD Grammar Systems.

In this paper, we introduce a dynamical complexity measure, namely the degree of team cooperation, in the aim of investigating "how much" the components of a grammar system cooperate when forming a team in the process of generating terminal words. We present several results which strongly suggest that this measure is trivial in the sense that the degree of team cooperation of any language is bounded by a constant. Finally, we prove that the degree of team cooperation of a given cooperating/distributed grammar system cannot be algorithmically computed and discuss a decision problem

XNorthwind : grammar-driven synthesis of large datasets for DB applications

Abstract: Relational databases often come with sample databases. One known example is the Northwind database, often used as data repository for software testing and development purposes. The Northwind database includes hypothetical records of customers, companies, products, employee and so on. The number of records in the Northwind is however considered inadequate for large applications, where a developer or user may need a lot more, possibly, millions of records. In this paper, we have used a Context-free Grammar in describing the rules for the synthesis of exponentially many hypothetical datasets that are similar to the Northwind database. We referred to the resulting database as XNorthwind (Extended Northwind). The new grammar was implemented, resulting in thousands of unique data values across the eight different Northwind Data Tables. These datasets will find applications in training and development environments. A survey of 112 participants’ perceptions showed that 94.6% agreed that the XNorthwind can be useful